Double Flange Double Eccentric Butterfly Valve

The turning center of the butterfly plate is on the center line of the valve body and the sealing face section of the butterfly plate. In closing, the ex-circle sealing face of the butterfly plate will extrude the valve seat made of synthetic rubber, generating elastic deformation on the seat to form an elastic force used as a sealing specific pressure so as to guarantee the tightness of the butterfly valve.

A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. The valve may also be opened incrementally to throttle flow.